CBSE 12TH BIOLOGY - Online Test
Q1. Vegetatively propagated plants are generally
Answer : Option C
Explaination / Solution:
In vegetative propagation is the asexual mode of reproduction in which plants parts are used to grow new plants. Since fusion of gametes is not involved in the process all individual produced vegetatively are genetically similar.
Q2. The first transgenic cow was
Answer : Option C
Explaination / Solution:
In 1997, the first transgenic cow, Rosie, produced human protein-enriched milk at 2.4 grams per litre. This transgenic milk is a more nutritionally balanced product than natural bovine milk and could be given to babies or the elderly with special nutritional or digestive needs.Rosie’s milk contains the human gene alpha-lactalbumin.
Q3. Which one of the following correctly matched STD with pathogen
Answer : Option C
Explaination / Solution:
Syphilis is caused by bacteria Treponemapallidum. AIDS are caused by HIV, Gonorrhea is by bacterium Neisseria gonorroeae. Uretheritis is not a sexually transmitted disease.
Q4. Which kind of embryo is shown in figure below
Answer : Option D
Explaination / Solution:
The zygote divides mitotically many times to form large number of cells. These cells arrange into different shape. The most common embryo is Globular embryo.
Q5. Age groups among human population includes all except
Answer : Option C
Explaination / Solution:
Age groups among human population includes reproductive, pre-reprouctive and post reproductive growth. It do not includes embryonic phase growth.
Q6. AIDS is caused by Human immuno deficiency virus (HIV) which is a member of group of virus called
Answer : Option B
Explaination / Solution:
Retrovirus, any of a group of viruses that belong to the family Retroviridae and that characteristically carry their genetic blueprint in the form of ribonucleic acid (RNA). Retroviruses are named for an enzyme known as reverse transcriptase, which was discovered independently in 1971 by American virologists Howard Temin and David Baltimore.
HIV virus belongs to this group as its genetic material is also RNA.
Q7. The strand of DNA that forms mRNA is called
Answer : Option D
Explaination / Solution:
During transcription, only one of the two DNA strands is copied. This is called the template strand because it acts as a template for the mRNA that is being assembled by the ribosomes. The sequence of the mRNA is complementary to the sequence of the template strand.
It is also known as sense strand.
Q8. Which one is an alternate source of proteins for animals and human nutrition?
Answer : Option A
Explaination / Solution:
Alternate source of proteins for animals and human nutrition is single cell protein. Microbes are grown on industrial scale as source of good protein. Microbes like Spirulina on waste water of potato processing plants.
Q9. Species which suffered a near-extinction from ingesting the carrion of diclofenac-treated cattle is/are:
Answer : Option D
Explaination / Solution:
These include the Asiatic lion, the Bengal tiger, the snow leopard and the Indian white-rumped vulture, which, by ingesting the carrion of diclofenac-laced cattle, nearly went extinct.
Q10. Each testis has about 250 compartment called as
Answer : Option D
Explaination / Solution:
Each testis contains about 250 compartments called testicular lobules. Each testicular lobule contains one to three highly coiled seminiferous tubules that produce sperms.
